Cardiorespiratory effects of acepromazine, xylazine and midazolam under different isoflurane concentrations in dogs

Abstract

The cardiorespiratory effects of three tranquilizer-isoflurane combinations were evaluated in six, healthy, male dogs (weighting 25,0 ± 27,7kg). Acepromazine (0,1mg/kg iv) or xylazine (1.0mg/kg iv) or midazolam (0.2mg/kg iv) followed by isoflurane (1.0; 1.5 and 2.0 MAC) were administered to each animal. Cardiovascular and respiratory parameters were measured at 5, 10, 15 and 20 minutes. The results were submitted to statistical analysis (analysis of variance, Pearson linear correlation and compared with Duncan test, p < 0.05). Cardiovascular depression was observed after acepromazine and xylazine administration. Xylazine produced highlier significantly respiratory depression than acepromazine. No significant changes were observed after midazolam administration at 1.0 and 1.5 MAC, but significant changes were observed on cardiovascular behavior at 2.0 MAC. We concluded that midazolam-isoflurane was the safest combination of this study, producing minimal depressant cardiopulmonary effects.